中文摘要：

本文利用Landsat TM和ETM＋遥感影像，基于知识规则的遥感分类及分类后处理方法对20世纪80、90年代末的半干旱的老哈河流域土地利用变化进行动态监测，并用GIS方法对土地利用变化及其空间分布进行了定量分析。结果表明：在这十年间，由于气候条件的变化及人类活动的影响，老哈河流域土地利用发生显著变化，变化范围占流域总面积的33．64％，土地利用变化主要表现为农、林、牧用地之间的转换。其中水体、滩地、林地、草地和未利用土地减少，大量的沙地和裸土地被开发利用；城乡用地和旱地有所增多，水田大幅度增加，农业耕作方式发生巨大变化。本研究为研究北方干旱化形成机理的生态一水文耦合模型提供重要的下垫面输入条件，为以后土地利用格局的改变对蒸散发和径流过程的影响提供重要的分析前提。

英文摘要：

Land use/cover change is one of the most important areas of global change. On the basis of the Landsat TM and Landsat ETM ＋ images and other auxiliary data, the rules of decision trees were developed in this study. Land use/cover classifications in 1989 and in 1990 were implemented based on the decision trees with satisfied accuracy. The land use changes from 1989 to 1999 and their spatial distribution were analyzed quantitatively with GIS techniques in semiarid Laohahe River Basin with a catchment area about 19,000km^2 in North China. The results show that in this period, distinct land use changes happened in the study area because of the impacts of climate change and human activities. The changed area accounted for about 33. 64% of the basin. The most important change was the conversion among agricultural lands, forest lands and grasslands. Water areas, bottomlands, forest lands, grasslands and fallow lands are decreased. And the fallow lands decreased especially seriously because large numbers of sandy lands and bare lands were exploited. Rural and urban areas, paddy fields and drycrop lands increased. The paddy field areas increased more than 10 times because of the change of agricultural cultivation. And rural and urban areas increased because of the expansion of Chifeng city. This study provides an important precondition for the study on the effects of land use change on evapotranspiration and hydrological processes in Laohahe River Basin.